rainsnowind
North Scottsdale, AZ
New Member
Joined: 01/04/2007
View Profile
 Offline
|
I am sure this has been posted numerous times but I cannot find a good post about it... Is an 80 watt solar panel enough to run a TV a few hours a day as well as lights a bit at night? I understand the Generac generators do not charge batteries when they run but the Onans do. Two separate questions, I know!
|
bldrbuck
Boulder, Colorado
Senior Member
Joined: 02/11/2001
View Profile
|
Eighty watts is about 6 amps. In really good sun with the panel tilted at the best angle that may barely charge your battery enough for what you want. It will be marginal at best. Using a generator to charge batteries works using your converter or an outside battery charger. Some honda have a 12 volt circuit but it puts out only a few amps.
|
hwybnb
Southern California
Senior Member
Joined: 05/02/2001
View Profile
|
Solar panel power ratings are calculated using Maximum Power Voltage (Vmp) times Maximum Power Current (Imp). An 80 watt panel will produce around 5 amps in a battery charging application. If you can get that much out of it for 6 hours a day it will add up to about 30 amp-hours. A television receiver running on an inverter will draw about 6 amps, so you could theoretically watch five hours worth on your 30 amp-hours. There are other factors of course but in a sunny location you should be able to get at least 3 or 4 hours use, if you don't have other loadslike lights, refrigerator, etc.
In summary it might work but bumping the power up to 120 watts would be better.
|
smkettner
Southern California
Senior Member
Joined: 03/21/2005
View Profile
Offline
|
You will be treading water at best with just 80 watts tilted to the sun on a cool and sunny summer day. It will allow you to go longer for sure. You may get 3 or four days out of the battery instead of 1 or two days without the panel. You will need to conserve a lot to keep the battery full on an 80w panel.
Generally generators do not charge batteries. Generators power a converter that charges the battery. You do need a good converter for a fast recharge. Some are great and others are miserable. Post the make and model to know how yours will do.
2001 F150 SuperCrew 5.4 Lariat Offroad 4x4 Tow Package 4.10 Truetrac
2006 Keystone Springdale 249FWBHLS
12K SuperGlide, KGE3000Ti 2.3kw rated 2.6kw max
Frank's voltage booster, Prosine 1800 powered by 4 GC2 batteries
|
pulsar
Lewisville, NC
Moderator
Joined: 12/30/2001
View Profile
|
Moved from Forum Technical Support to Tech Issues.
2002 Adventurer 32V - Workhorse chassis
1998 CRV toad - manual transmission
Have you seen the RV.Net Blogs? You can subscribe at Blog.RV.Net
|
|
|
Golden_HVAC
Fulltime, CA, USA
Senior Member
Joined: 08/19/2003
View Profile
Offline
|
hwybnb wrote:Solar panel power ratings are calculated using Maximum Power Voltage (Vmp) times Maximum Power Current (Imp). An 80 watt panel will produce around 5 amps in a battery charging application.
If you can get that much out of it for 6 hours a day it will add up to about 30 amp-hours. A television receiver running on an inverter will draw about 6 amps, so you could theoretically watch five hours worth on your 30 amp-hours. There are other factors of course but in a sunny location you should be able to get at least 3 or 4 hours use, if you don't have other loadslike lights, refrigerator, etc.
In summary it might work but bumping the power up to 120 watts would be better.
This information is very good. However it leaves out that the RV itself will be using 30 amp hours each day, and that the lights will use perhaps another 20 amp hours of power.
Your generator - regardless of the brand will recharge the batteries if the battery charger is working. Most modern battery chargers are in the 30 to 55 amp range, and will do a fairly quick job of refilling the batteries. If your RV is less than 15 years old, it should have an electronic battery charger, but older ones (before 1989) have "Converters" that only have a 5-7 amp battery charge circuit, and are not regulated very well, so a generator putting out 105 volts will not produce any effective recharge, while one putting out 125 volts can overcharge the batteries.
Your part is to make sure that the cells are full of distilled water, and that you run the generator about 1 hour in the morning and near nightfall.
The charger will usually refill the batteries at a rate around 30 amp hours per hour. (Yes even my 70 amp charger will slow down to 30 amps after an hour - it starts out faster, but the amperage falls off quickly as the batteries begin to fill up.)
So if you run the generator about 2 hours per day, you will make up for the power consumed by the refrigerator, propane and carbon monoxide detectors (about 1.5 amps per hour in my RV) and some of the lights.
You don't need to refill the battery completely, save that for when you have electric shore power, and let it recharge for about 24 hours, to refill the batteries to 100% and break up any sulfur deposits on the lead plates.
If you want to dry camp for weeks at a time, then I would recomend a pair of 120 watt solar panels. That will make up for all of your uses, without need to listen to the generator.
SolarOnSale.com
Fred.
Money can't buy happiness but somehow it's more comfortable to cry in a Porsche or Country Coach!
If there's a WILL, I want to be in it!
Improve a life KangenPowerTeam.com Akaline Water.
I havn't been everywhere, but it's on my list.
Escapees.com
|
wa8yxm
Wherever I happen to park
Senior Member
Joined: 07/04/2006
View Profile
Offline
|
First: Generators: Do not charge batteries when they run, don't matter if they are Genrac, Onan, Kipor, Honda, Or _____ they don't, as a rule, charge batteries.. They do, however, provide power to the rig's converter and IT does charge the batteries.. So when your generator is running your batteries should be charging.
Many of the portable generators including the ones listed above often have 12 volt outlets or terminals for battery charging.. Forget those, they are a joke, plug the rig in and let the converter do it's job. That's what it's there for
now 80 watts.. In bright sun you can expect to get, at best, half the rating of the panel. So that's 40 watts. You can expect perhaps 10 hours a day and during most of those you will not be getting full output, so count on perhaps 300 watts a day.... Divide by the power requirements of your TV and you now know how long you can run it,, Oh, take 10 % off the top for losses make it 270 watts.
Nothin adds excitment like something that is none of your business
Kenwood TS-2000 housed in a 2005 Damon Intruder 377
|
robatthelake
Vancouver Island
Senior Member
Joined: 08/24/2003
View Profile
Offline
|
We have 3X75 Watt Panels and 6X6 Volt Golf Cart Batteries on Our Rig! We watch TV and use minimal Lights from Dusk until 11 PM or so aprox 4 1/2~5 Hours. We have survived for over 6 Weeks at a stretch , while Dry Camping in Mexico with Zero Engine use and very little genset maybe 15 Minutes twice a week to use the Microwave and a Coffee Maker!
Granted that's in Mexico where the Sun shone daily and We used Propane to Cook & Refridgerate!
If I Needed to use a generator to recharge I would plug My Automotive Battery Charger in and use that instead of the Convertor!
Rob & Jean 90 Southwind John Deere/Oshkosh/Freightliner Class A Ford 460/ Toad 92 Tracker 2 wd 5sp Convert Still running Great!
" Everything in it"Still" Works"
|
